Self Assigned IP Address

I'm running an iMac, and a Macbook Pro 13" (iMac - Leopard, Macbook Pro 13" - Snow Leopard). My internet setup is an At&t 2-Wire 2701hg. I am able to connect the iMac through airport, but my MBP is unable to connect because it says under the network tab that it has a self-assigned IP address. I have tried taking off the firewall (it is currently off), resetting the router, and deleting my prefs from the Library (which by the way I couldn't find the one for airport). Hoping to get this thing up and running, and I appreciate any assistance.

Are you connecting both the iMac and the MBP via WiFi (Airport)? Do you have DHCP enabled in the 2701HG? I have that router here as a back up in case my modded Linksys ever dies and have messed with it a lot.

If you reset that 2701HG it should be set DHCP be default and should hand out IP Address's. Are you sure the MBP is set for DHCP? Under Network, Airport, Advanced and TCPIP be sure NVP4 is set to DHCP.

Also what happens if you plug in the MBP into one of the network ports on the 2701HG. Do you get an IP address then?